The structures of many prokaryotic and eukaryotic NBDs have been solved, providing templates to understand the ATP-binding and hydrolysis cycles associated with normal ABC-transporter activity.
Links below provide the current inventory of NBDs available in the PDB as well as canonical NBD structures in ATP bound and free states and as monomers and ATP-induced NBD dimers.
Canonical NBD Structures
HisP NBD - the first solved NBD from an ABC transporter, the bacterial histidine permease. This core fold of this domain defines the ABC-transporter family of proteins.
Mj0796 nucleotide-sandwich dimer - the first physiologically relevant dimer structure of ATP-bound NBDs. This structure provides a critical model for understanding the catalytic cycle and hydrolysis chemistry of the ABC proteins.